Clothes dryer lint separator



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STEPHEN L. MC'MILLAN H IS ATTORNEY llnited States Patent O CLOTHES DRYER LINT SEPARATOR Stephen L. McMillan, Louisville, Ky., assigner to General Electric Company, a corporation of New York Application September 1I), 1954, Serial No. 455,280 7 Claims. (Cl. 34-79) This invention relates to clothes dryers, and more particularly to a lint trap for the exhaust air stream to extract dust and lint particles from the air before it is discharged.

An object of my invention is to provide a lint trap structure which offers minimum impedance to air flow, and which does not have any tendency to load up with lint particles and thereby partially block or restrict air ow.

It is a further object of this invention to provide a lint trap structure effectively separating lint from discharged air, retaining the lint in a storage area of substantial volume, and providing a construction easily cleaned by the operator.

Still another object of this invention is to provide a clothes dryer for removing lint from discharged air more eifectively than heretofore possible with screen type devices. t

In carrying out this invention in one form as applied to a clothes dryer having means for forcing air through the clothes being dried, I provide a longitudinally extending lint extractor which imparts a swirling or spiral motion to incoming lint laden air to extract lint centrifugally.` The air is permitted to escape through an outlet conduit projecting centrally into the extractor, preferably to a point beyond the inlet opening, so that the lint laden air must iiow at high speed through several turns before passage into the outlet conduit. The extracted lint may be collected in an enlarged container at an end of the device remote from the inlet and outlet to the extractor.

The features of my invention which I believe to be novel are set forth with particularitytin the appended claims. The `invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may` best be understood by `reference to the following description taken in connection with the accompanying drawing, in which Fig. 1 is a front elevation, with certain surfaces broken away to illustrate detail and partially in section, of a clothes dryer embodying my invention; Fig. 2 is a top `plan View, again with certain surfaces broken away and partially sectionalized to illustrate details; and Fig. 3 is a partial cross-sectional View taken on the line 3-3 of Fig. l looking in the direction of the arrows.

Referring now to the drawings, I have shown my invention as embodied in a clothes dryer of the domestic type, including a rotatable clothes tumbling basket 1 mounted within an outer enclosing cabinet structure including side walls 2, a front wall 3, a top panel 4 and a suitable base 5. Front panel 3, in the usual manner, includes a suitable loading opening adapted to be closed by a hinged door 6. Basket 1 is a cylindrical drum-like member with an enclosing rear wall 7 with a series of perforations 8 to `admit air into the basket, an outer cylindrical wall 9 substantially imperforate over its entire area, and a front wall 10 having aflanged loading opening 11 therein in substantial alignment with the front access opening through the cabinet.

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In accordance with this particular embodiment, clothes basket 1 is rotatably supported within the cabinet on anged roller wheels 12, 13, 14 and 15. Flanged wheels 12 and 13 are carried on an idler shaft 16 rotatably mounted in front and rear brackets 17 andl 18 secured to the outer cabinet structure. complished through the roller wheels 14 and 1S secured to a driving shaft 19, likewise rotatably supported with respect to the cabinet by front and rear brackets 20 and 21 respectively. Also secured to driving shaft 19 is a driving pulley 22 driven by a belt 23 from any suitable motive power source such as motor 24. With this arrangement, it is seen that basket 1 may be .driven at an appropriate speed to provide a tumbling action for articles of clothing placed within thebasket.

Moisture is evaporated from clothes being tumbled within the basket by the combined effects of radiation and convection from a heater assembly designated generally by 25. This heater assembly in the form of a pan-type unit is located coaxially of basket 1 and is supported from a rear wall 26 of the cabinet by a main central bracket 27 and auxiliary bracing means 28. The electrical resistance Wire 29 is supported on a plurality of insulating members 30 carried by a pan-like support-` ing and reflecting structure 31. As clearly shown by Fig. 2, this pan-like structure 31 tends to reflect all of the radiant heat from the resistance coil.29 toward the interior of the drying basket. practice that means must `be provided to limit the maximum temperature of the rear wall of the clothes basket to obviate scorching of the clothes. This may be accomplished conveniently by use of an oppositely positioned pan-like member 32 of slightly larger diameter having a plurality of apertures 33 therein through which radiant energy may pass and also through which heated air may flow. This oppositely directed disc 32,` preferably of metal, may have a plurality of annular spacing ribs 34` to limit the metallic contact 'and hence the heat conduct-` the basket. Also, with this construction there is no direct metallic heat conduction path between the electrical heating element assembly and the rear wall of the basket which is in contact with thetarticles being dried; As` shown by Fig. 2, this heating element construction is also arranged to provide numerous air flow paths so that in-g coming air may flow over the highly heated parts before entry to the basket throughapertures 8. Additionally,` the rear wall of basket 1 may be provided with one or more annular ribs 37, which during tumbling action, tend4 to deect articles of clothing away from the central portion of the rear wall, since in spitetof these precautions as described above there is still artendency for the `rear basket wall to reach a higher temperature than other portions of the tumbling basket.

This particular heater `construction has been described herein to form a background-for a proper understanding l of this invention. It does not, however, form a part `of:` my invention, but is disclosed and` claimed inthe copending application of Eugene G. Olthuis,.Serial No. `523,084

sied `July 19, t 1955, new `Patent Ntra190,247,` and as. f. signed to `theGeneral Electric Compantassignee of,

application.

The basket drive is ac-` However, it is found in Therefore, there is no direct radiation from, the electrical heating element tothe rearl metallic wall `of- The same motive power source 24 employed to rotate basket 1 may also be employed 'to drive a blower or other suitable air impelling device 38. As clearly shown by Fig. 2l, the outlet from the blower-is connected to a flexible du'c't 39 which may be oriented for discharge from the dryer cabinet to any desired point. It is the function of blower 38 to draw air into the machine, whereby it enters the tumbling basket after passing over the highly heated surfaces associated 'with the heating element assembly 2S, to extract moisture 'from the articles 4of clothing being tumbled within vthe basket. The blower withdraws the air employed for drying from the basket through a discharge passage member 40 and through a ylint trap structure indicated generally at 41 into 'the blower inlet through a flexible conduit 42. Other types of 'air impelling devices could, of course, be used; it being essential to this Ainvention only that a means be employed for moving air through the machine. In accordance with this particular structure, l have shown no special air inlet apertures, although obviously louvre's or other 'air inlet openings might be provided, for example in rear wall 26 of 'the device. However, it is found inv practice that the sheet metal construction of the outer cabinet may easily provide 'a number of small air inlet openings at various points, such as the junction be tween overlapping panel 'sections and the like. It is, in fact, preferred that air does enter the machine through such lopenings so that the incoming air may now over the inner walls of the cabinet structure, and thereby maintain the cabinet at a safe and comfortable temperature level. The machine is `constructed so that the only air inlet into the basket or clothes container is through the apertures in the rear wall thereof. Hence, all air entering the basket must iiow over the highly heated surfaces of the heating element assembly to extract the heat therefrom. Also, there' is a substantial transfer of radiant energy through the aligned apertures directly into the clothes basket.

The discharge passage through which air is withdrawn from the tumbling vbasket extends downwardly to the lint trap assembly in 'thefor'm of "an enclosed duct 43 secured inside front wall 3 of the cabinet, as shown for example in Fig. 3. Duct 43 'converges laterally as it extends downwardly, and it has substantially the same lateral dimension as the access door 6 -at its upper end. The discharge passage 43 is, 'of course, substantially imperforate with the exception of a plurality of perforations v44 on the inside upper wall 'portion thereof over the area presented to the loading opening 11 of the tumbling basket. Hence, `air drawn through the tumbling basket enters 'at the rear wall thereof and passes generally axially 'through the basket to the discharge openings 44 in the duct member 43.

As` shown most clearly by Fig. 1, the duct member 43 may also provide a convenient location for a suitable automatic control assembly 45 having a control knob 46 projecting upwardly through the upper wall 47 of this discharge duct. This location of the temperature sensitive control is particularly advantageous since it is directly in the air discharge stream from the dryer basket, so that it tends to sense rather closely the temperature of the clothes themselves. I have not shown or described this temperature sensing control in any detail herein, since it forms the subject matter of a separate application Serial No. 523,083, l'ed July 19, 1'955, of Eugene G. Olthuis assigned to the General Electric Company, assignee of this application.

As shown by Fig. l, the air discharge conduit 43 converges `as it extends downwardly vinto a nozzle portion 48 opening tangentially through an orifice 49 into the lint trap assembly. (See Fig. 3.) By employing a blower of suitable capacity, and by decreasing the cross sectional area of conduit 43 approaching 'the nozzle, a relatively high air velocity, vfor example in excess of l2 feet per second, is attained at 'the orifice.

The lint trap assembly comprises a relatively large diameter outer member or conduit 50, preferably inclined slightly from the horizontal, into which inlet nozzle 49 opens tangentially. In the particular arrangement shown by Fig. l, the outer conduit 50 extends laterally of the machine a substantial distance, adjacent and generally parallel to front wall 3, terminating at its lower end in a compartment 51 of substantial volume disposed adjacent and generally parallel to a side wall 2, i. e., at a substantial angle, and preferably a right angle, to the front wall. Compartment 51 may include a removable drawer having a knob 52 by 'which it may be removed for cleaning. The opposite end 53 of outer conduit 50 receives substantially coaxially an inner open-ended conduit 54, but is otherwise enclosed. As clearly shown, inner conduit V54 is connected by the flexible connection 42 with the axial inlet into blower 38.

As shown by Fig. 1, the inlet section 48 into the lint trap structure is adjacent the closed end 53 of the outer conduit. Also, as shown in Fig. 3, this inlet into the lint trap structure enters the outer conduit tangentially, thereby imparting a swirling or spiraling motion to the incoming air. Referring again to Fig. l, the air outlet or inner conduit 54 vfrom the lint trap structure extends axially inwardly and centrally located within outer conduit 50 through the closed end to an extent longitudinally of the outer conduit exceeding the axial or longitudinal dimension of the air inlet 48, Thus, the relatively high velocity air entering the outer conduit spirals toward the enlarged compartment 51 at the opposite end from the inlet and outlet openings. The entrained lint and dust particles in the air, being heavier than air, are thrown to the outside by centrifugal force and are carried both by the motion of the air and by the downward inclination of the outer duct into the enlarged compartment 51. By virtue of the larger volume of compartment 51 and also, in view of its relative position with respect to outer conduit 50, the air velocity therein is greatly reduced, and in fact by providing a drawer-like structure extending a substantial distance from front to rear in the machine, a large volume is provided in which lint may be accumulated. When this swirling mass of air in the outer conduit strikes the closed end 55 thereof, its direction of flow is reversed, and the spiraling action continues, thereby forming an inner spiral or swirling mass of air moving generally in the direction of the outlet duct 54. This motion is, o'f course, facilitated by the fact that blower 38 is exerting a suction through conduits 42 and 54. Thus, any lint particles which remain in the air as it is drawn toward the loutlet conduit 5'4 tend to be thrown outwardly, so that the air finally entering outlet conduit 54 is substantially free from entrained lint and dust particles.

Theoretically, and of 'course within practical limits, the higher the air velocity, the more effective is the lint extraction. While air velocities from 60 to 100 feet ,per second might appear to be desirable on a theoretical basis, it is found in actual practice that much lower velocities can be used with satisfactory results. For example, in one form of clothes dryer employing a lint trap or extractor along the lines disclosed herein, and with components limited in size by application to a device suitable for domestic use, it was found that air velocities of l2 to 15 feet per second within the outer conduit were sufiicie'nt to provide satisfactory removal of the lint from the air.

It is also desirable that the outer conduit 50 have a substantial length compared with the longitudinal dimension of the inlet nozzle, in order to allow several spirals 'or turns of the incoming air prior to its arrival at the closed end of the outer conduit. This allows greater time for the lint particles to move outwardly whereupon they are carried into the dead air zone of the larger compartment. While I have shown herein the larger compartment in the form `of a drawer, this is not essential and it is found that other types of enlarged compartments at the closed lend ofthe outer conduit also function to 'receive the lint and prevent its withdrawal as the air returns toward the outlet from the lint trap structure. It is essential, however,

that this lint receiving 'compartment have a substantially greater volume than the adjacent portion of the outer conduit, so that there is a substantial volume into which the lint may pass and in which the air velocity is substantially decreased. The use of a large lint collecting compartment has the further advantage, of course, that a substantial quantity of lint can be accumulated without interfering or mpeding in any way with the operation of the dryer. In no case does the accumulation of lint within the storage area of the lint trap assembly interfere with air flow through the machine.

While I have described this invention with reference to a particular embodiment thereof, it is to be understood that numerous modifications may be m-ade by those skilled in the art Without actually departing from the invention. It is, therefore, the aim of the appended claims to cover all such equivalent variations as come Within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. In a clothes dryer, an outer enclosing cabinet having front and rear end walls and side Walls, air heating means, a clothes container, air circulation means for inducing air ilow from an inlet over said heating means and through said container, a discharge passage from said clothes container, an elongated duct closed at one end and having an inlet through the side wall thereof adjacent said end cornmunicating with said discharge passage, said duct being disposed yadjacent one of said end walls of said cabinet and extending generally parallel to said one wall, means imparting a swirling motion to air entering said duct thereby to extract lint from the air centrifugally, a removable container associated with the opposite end of said duct, said container including a substantial volume and extending at a substantial angle relative to said duct to provide -a quiet zone of relatively low air velocity for collection of lint extracted centrifugally, said container being disposed adjacent one of said side walls of said cabinet and extending generally parallel thereto, and an air outlet pas- -sage extending into said duct through said closed end thereof and substantially centered with respect thereto.

2. In a clothes dryer, an outer enclosing cabinet having front and rear end walls and side walls extending generally perpendicular to said end walls, air heating means, a clothes container, air circulation means for forcing air from an inlet over said heating means and through said container, a discharge passage from said clothes container, an elongated duct closed at one end and having an inlet through the side wall thereof adjacent said end communicating with said discharge passage, said duct extending generally parallel to a rst of said walls of said cabinet and being disposed adjacent thereto, means imparting a swirling motion to air entering said duct thereby to extract lint from the air centrifugally, a container communicating with the opposite end of said duct to provide a quiet zone of relatively low air velocity for collection of lint extracted centrifugally, said container extending at substantially a right angle relative to said duct thereby to cause the air to flow at a relatively low velocity therein, and being disposed adjacent one of said walls of said cabinet extending generally perpendicular to said rst wall, and an air outlet passage extending into said duct through the one closed end thereof an axial distance exceeding the corresponding dimension of said inlet, said air outlet passage being substantially centered with respect to said duct.

3. In a clothes dryer having heating means and means impelling air into the dryer and over the heater, and means for exhausting said air to the outside of the dryer, a lint separator comprising an outer conduit having smooth` interior walls and a closed end, said outer conduit extending in a direction inclined slightly from the horizontal, a generally tangential air inlet to said outer conduit adjacent said closed end, an open-ended inner conduit extending axially into said outer conduit a distance exceeding the axial length of said air inlet, the outer end of said inner conduit forming an air outlet from the lint separator, and an enlarged enclosed lint collecting container at the opposite end of said outer conduit, said lint collecting container extending at a substantial angle relative to said outer conduit thereby to cause the air to flow at a relatively low velocity therein for the settling of lint and said container including a slidably mounted drawer arranged for removal from said dryer for cleaning.

4. In a clothes dryer, heating means, means impelling air into the dryer and over the heater, and means for exhausting said air to the outside of the dryer, in combination with a lint separator comprising an outer conduit having smooth interior walls and a closed end, said conduit extending in a direction inclined slightly from the horizontal, a generally tangential air inlet to said outer conduit adjacent said closed end, an open-ended inner conduit extending axially into said outer conduit a distance exceeding the axial length of said air inlet, the open end of said inner conduit forming an air outlet from the lint separator, and an enlarged enclosed lint collecting chamber at the opposite end of said outer conduit, said enlarged enclosed lint collecting chamber being in the form of a removable drawer and extending at substantially a right angle to said outer conduit thereby to cause the air to flow at a relatively low velocity therein for the settling of lint, said drawer being slidably mounted for removal from said dryer for cleaning.

5. A clothes dryer comprising a dryer drum including a loading opening in the front Wall thereof, heating means, air circulating means for forcing air from an air inlet over said heating means and through the dryer drum, an exhaust duct from said dryer drum communicating with said drum through said loading opening, an outer conduit having a closed end and into which said exhaust duct discharges tangentially adjacent said closed end, said conduit extending generally parallel to the front of said dryer, an enlarged lint container at the opposite end of said conduit, said lint container extending along one side of said dryer at substantially a right angle to said outer conduit to provide a zone of low air velocity for the settling of lint, a discharge passage extending through said closed end coaxially into said outer conduit an axial distance at least equal to the axial length of said exhaust duct.

6. A clothes dryer comprising a dryer drum, heating means, air circulating means for forcing air from an air inlet over said heating means and through the dryer drum, an exhaust duct from said dryer drum having a 4relatively large mouth and narrowing to an orifice to increase air velocity, an outer conduit having a closed end and into which 4said exhaust duct orifice discharges tangentially adjacent said closed end, said exhaust duct narrowing from said mouth to said orifice in a manner Whereby said mouth communicates with said drum across a greater length than said orifice extends axially along said conduit, an enlarged lint container at the opposite end of said outer conduit, and a discharge passage extending through said closed end centrally into said outer conduit a distance at least equal to the axial length of said orifice.

7. A clothes dryer comprising a dryer drum, heating means, air circulating means for forcing air from an air inlet over said heating means and through the dryer drum, an exhaust duct having a relatively large mouth communicating with the dryer drum and narrowing to an orifice to increase air velocity to at least l2 feet per second, an outer conduit having a closed end and into which said exhaust duct orifice discharges tangentially adjacent said closed end, said exhaust duct narrowing from said mouth to said orice in a manner whereby said mouth communicates with said drum across a greater length than said orice extends axially along said conduit, an enlarged lint container at the opposite end of said conduit providing a relatively quiet air zone for collection of lint, and a discharge passage extending through the closed end of said outer conduit centrally located with respect thereto and extending longitudinally into said outer conduit a dis- '2?' 8 tance at least equal fto the corresponding dimension 1of=said 1,791,038 Opavsky Feb. 3, 1931 orifice. 2,378,600 Van Tongeren June 19, 1945 2,437,592 Brown Mar. 9, 1948 References Cited in the le of this patent 2,509,300 Hendrickson May 30, 1950 UNITED STATES PATENTS 5 2,623,299 Kauffman Dec. `50, 1952 1,530,073 Cutter Mar. 17, 1925 

